Vascular Responses to Vasopressin Antagonists in Man and Rat

1994 ◽  
Vol 87 (4) ◽  
pp. 389-395 ◽  
Author(s):  
Louise M. Burrell ◽  
Paddy A. Phillips ◽  
K. A. Rolls ◽  
B. F. Buxton ◽  
C. I. Johnston ◽  
...  

1. The effects of the non-peptide arginine vasopressin V1 receptor antagonist (OPC-21268) and the non-peptide V2 receptor antagonist (OPC-31260) on vasopressin-induced contraction of human internal mammary arteries and rat mesenteric resistance arteries were investigated. 2. In human internal mammary arteries, the non-peptide V1 receptor antagonist, OPC-21268, failed to antagonize vasopressin-induced contraction at low concentrations and potentiated the contraction at higher concentrations (300 nmol/l, P < 0.05). A peptide selective V1 receptor antagonist {[d(CH2)5, sarcosine7]arginine vasopressin} potently inhibited the vasopressin-induced contraction, indicating the presence of functionally constrictor V1 receptors in human internal mammary arteries. Both peptide (desGly-NH29[d(CH2)5, D-Ile2, Ile4]arginine vasopressin) and non-peptide ‘selective’ V2 receptor antagonists (OPC-31260, 3 μmol/l) significantly antagonized vasopressin-induced contraction (P < 0.01), indicating partial V1 receptor antagonist activity. 3. The vasopressin-induced contraction in human internal mammary arteries was reversed by high concentrations of the non-peptide V2 receptor antagonist, OPC-31260, but not by the non-peptide V1 receptor antagonist, OPC-21268. 5. In rat mesenteric resistance arteries, both OPC-21268 (10 nmol/l) and OPC-31260 (1 μmol/l) antagonized vasopressin-induced contraction (P < 0.01). 6. The results of this study in vitro indicate that in human internal mammary arteries, the non-peptide OPC-21268 is a partial V1 receptor agonist with no V1 receptor antagonist activity, whereas the non-peptide OPC-31260 acts as a V1 receptor antagonist. Both OPC-21268 and OPC-31260 have V1 receptor antagonistic activity in vitro in the rat mesenteric resistance arteries. 7. These findings illustrate the complexity of the vasopressin receptor system and highlight the variability in results with peptide or non-peptide vasopressin analogues, between studies in vivo or in vitro, between species and across vascular beds.

1993 ◽  
Vol 265 (4) ◽  
pp. R934-R942 ◽  
Author(s):  
M. Naitoh ◽  
H. Suzuki ◽  
M. Murakami ◽  
A. Matsumoto ◽  
A. Ichihara ◽  
...  

In conscious dogs, 36-h water deprivation induced a significant increase in renal blood flow (RBF) with elevation of the plasma arginine vasopressin (AVP) concentration to 9.6 +/- 1.8 pg/ml. To simulate such a condition, a mild elevation of plasma AVP was produced by infusing AVP intravenously at a dose of 0.1 ng.kg-1.min-1 for 20 min. The plasma AVP concentration then increased to 6.8 +/- 0.7 pg/ml. This dose of AVP increased the RBF by 21.7 +/- 2.6% and decreased the renal vascular resistance by 18.1 +/- 2.3% without significant changes in mean arterial pressure, cardiac output, or heart rate. The mechanism of this renal vasodilatory action was examined using newly developed, orally effective, selective AVP antagonists OPC-21268 (a V1-receptor antagonist) and OPC-31260 (a V2-receptor antagonist). In 36-h water-deprived dogs, V2-receptor blockade with OPC-31260 significantly decreased the RBF by 20.5 +/- 2.6% without significant changes in cardiac output. The exogenous AVP-induced renal vasodilatory response tended to be augmented when V1 receptors were blocked by pretreatment with OPC-21268, but the change did not achieve statistical significance. On the other hand, V2-receptor blockade by either pretreatment with OPC-31260 or simultaneous infusion of OPC-31260 inhibited this vasodilatory response. Furthermore, intravenous infusion of 1-desamino-8-D-arginine vasopressin (DDAVP) at a dose of 0.3 ng.kg-1 x min-1 for 20 min significantly increased the RBF by 36.5 +/- 1.7%, and this DDAVP-induced renal vasodilation was inhibited by simultaneous infusion of V2-receptor antagonist.(ABSTRACT TRUNCATED AT 250 WORDS)


1999 ◽  
Vol 381 (1) ◽  
pp. 23-30 ◽  
Author(s):  
John Risvanis ◽  
Mareo Naitoh ◽  
Colin I Johnston ◽  
Louise M Burrell

1995 ◽  
Vol 89 (5) ◽  
pp. 481-485 ◽  
Author(s):  
James J. Liu ◽  
Joan R. Chen ◽  
Brian B. Buxton ◽  
Colin I. Johnston ◽  
Louise M. Burrell

1. The effect of vasopressin receptor antagonists varies between analogues (peptide, non-peptide) and across species. In this study the effect of the novel non-peptide vasopressin V1a receptor antagonist SR 49059 on human internal mammary arteries was investigated. 2. SR 49059 produced a potent, concentration-dependent, inhibitory effect on vasopressin-induced contraction of human coronary bypass graft internal mammary arteries. Both SR 49059 (1 μmol/l) and a peptide selective V1a antagonist {[d(CH2)5sarcosine7]arginine vasopressin} (1 μmol/l) abolished vasopressin-induced contraction. The non-peptide V1a receptor antagonist OPC-21268 (1 μmol/l) had no effect on vasopressin-induced contraction. 3. The effect of SR 49059 was specific to vascular vasopressin receptors as noradrenaline-induced contraction was not influenced by SR 49059. 4. The results of this study in vitro indicate that the non-peptide SR 49059 is a potent, specific vasopressin V1a receptor antagonist in the human internal mammary artery and suggest that it may be a useful tool for studying the pathophysiological role of vasopressin in man.


2017 ◽  
Vol 21 (9) ◽  
pp. 1767-1780 ◽  
Author(s):  
Grazia Tamma ◽  
Annarita Di Mise ◽  
Marianna Ranieri ◽  
Ari Geller ◽  
Roberto Tamma ◽  
...  

2018 ◽  
Vol 16 (1) ◽  
pp. 614-620
Author(s):  
Haitham Alrabiah ◽  
Mohammed Abunassif ◽  
Sabry Attia ◽  
Gamal Abdel-Hafiz Mostafa

AbstractA new, selective and sensitive HPLC method for the determination of lixivaptan, an oral selective vasopressin 2 (V2)-receptor antagonist, was investigated and validated. A Waters symmetry C18 column was used as a stationary phase in isocratic elution mode using a mobile phase composed of KH2PO4 (100 mM)-acetonitrile (40: 60, v/v) at a flow rate of 1.5 mL min-1. Diclofenac was used as the internal standard (IS). Lixivaptan and the IS were extracted from plasma by protein precipitation and were detected at 260 nm. Lixivaptan and diclofenac were eluted at 3.6 and 6.2 min, respectively. The developed method showed good linearity over the calibration range of 50 -1000 ng mL-1 with a lower limit of detection of 16.5 ng mL-1. The extraction percentage of lixivaptan in the mouse plasma was in the range of 88.88 - 114.43%, which indicates acceptable extraction. The aforementioned method was validated according to guidelines of the International Council on Harmonization (ICH). The intra- and inter-day coefficients of variation did not exceed 5.5%. This method was presented to be simple, sensitive, and accurate and was successfully adapted in a pharmacokinetic study of the profile of lixivaptan in mouse plasma. A mean maximum plasma concentration of lixivaptan of 113.82 ng mL-1 was achieved in 0.5 h after oral administration of a 10 mg kg-1 dose in mouse as determined using the developed method.


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